\documentclass{standalone}
\usepackage{tikz}
\usepackage{ctex,siunitx,mhchem}
\setCJKmainfont{Noto Serif CJK SC}
\usepackage{tkz-euclide}
\usepackage{amsmath}
\usetikzlibrary{patterns, calc}
\usetikzlibrary {decorations.pathmorphing, decorations.pathreplacing, decorations.shapes,}
\begin{document}
\small
\begin{tikzpicture}[>=latex,scale=1.0]
  % \useasboundingbox(-1,1.2)rectangle(5,2.8);
  \draw[gray](-1.875,1.1255)--(-1.875,-2.2)--(-2.5,-3)(1.875,1.1255)--(1.875,-2.2)--(2.5,-3)(-1.875,-2.2)--(1.875,-2.2);
  % \fill[cyan!30,opacity=0.5](-1.875,0.8)--(-2.5,0)--(-2.5,-3)--(2.5,-3)--(2.5,0)--(1.875,0.8)--cycle;
  \fill[brown!90!red](-2,0)--++(0,-2.5)--++(0.5,0.8)--++(0,2.5)--cycle;
  \fill[brown!90!red](2,0)--++(0,-2.5)--++(-0.5,0.8)--++(0,2.5)--cycle;
  \draw[gray](-2.5,0)--(2.5,0);
  \foreach \x in {0.0875,-0.5375,-1.1625,-1.7875}
  {
    \node at (-1.75,\x)[circle,draw,inner sep=0pt] {\tiny$-$};
    \node at (1.75,\x)[circle,draw,inner sep=0pt] {\tiny$+$};
  }
  \foreach \x/\y in { 1.209/-0.346, 1.193/-0.985, 0.041/-1.607,-0.775/-1.164,-0.832/-1.747}
  {
    \draw[thin,->](\x,\y)--++(-0.4,0)node[midway,above]{\tiny\ce{Cu^{2+}}};
    \fill[ball color=blue](\x,\y)circle(2pt);
  }
  \foreach \x/\y in { -1.213/-0.557,-0.277/-0.191,-0.145/-1.062,-1.065/-2.448, 1.304/-2.416}
  {
    \draw[thin,->](\x,\y)--++(0.4,0)node[midway,above]{\tiny\ce{Cl-}};
    \fill[ball color=red](\x,\y)circle(2pt);
  }
  \fill[cyan!50,opacity=0.5](-1.875,0.8)--(-2.5,0)--(-2.5,-3)--(2.5,-3)--(2.5,0)--(1.875,0.8)--cycle;
  \draw[fill=cyan!20!lightgray,fill opacity=0.3,draw=black](-1.875,1.1255)--(-2.5,0.3255)--(-2.5,-3)--(2.5,-3)--(2.5,0.3255)--(1.875,1.1255)--cycle;
  \draw(-2.5,0.3255)--(2.5,0.3255);
  \draw[brown,thick,rounded corners](-1.75,0.4)--++(0,1.0)--++(-1,0)node[above right,text=black]{阴极};
  \draw[brown,thick,rounded corners](1.75,0.4)--++(0,1.0)--++(1,0)node[above left,text=black]{阳极};
  \end{tikzpicture}
\end{document}